The present invention relates generally to curtains for motor vehicle windows, and more particularly, to louver blind type curtains.
DE 35 05 143 describes a gathered curtain for motor vehicle windows which are non-rectangular in shape. The arrangement includes two guide tracks which run along long edges of the window and whose separation changes toward one end of the window. In each of the guide tracks, sliders run which are connected with the curtain.
The curtain is sized in such manner that it covers the window in the stretched out form. Consequently, when the curtain is gathered, those parts of the curtain which cover the broader part of the window are too long. The result is an aesthetically unpleasing sack-like appearance when the curtain is in the gathered condition.
WO 00/63517 describes a louver blind type curtain for windows in buildings. The louvers of the blind are suspended on sliders which run in a top guide track. From there, the louvers hang freely downward. At their lower edge, they are connected to each other by means of bead chains to achieve a certain stabilization. Each slider contains an angular gearing by means of which the angular position of the louvers with respect to the plane of the window can be changed to regulate the entry of light.
In addition to this adjustable rotative positioning, the louvers also can be moved in the longitudinal direction. For this purpose, the sliders contain cord rolls on which the pull cords can be wound and which pass through the rotation axis on which the louvers are suspended.
Based on the above, the problem to which the present invention is directed is to provide a louver blind type curtain which is suitable for use in the windows of motor vehicles where the shape of the window differs from that of a simple rectangular shape.
It is an object of the present invention to provide a louver blind type curtain adapted for effective use in non-rectangular-shaped motor vehicles. A related object is to provide a novel louver which accommodates the change in required louver length upon opening and closing of the blind.
In carrying out the invention, a louver is provided which consists of two louver parts, which can be adjusted with respect to each other in a longitudinal direction. One front end of each louver part or section forms the top end of the louver. By means of a pre-tension device, the louver parts are subjected to a pre-tension with respect to each other. The pre-tension device prevents clattering of the parts from knocking against each other as they move in the guide tracks. Without such a pre-tension force, the louvers would have a tendency to clatter against themselves and in their guide tracks when the vehicle is in use.
Louvers which are used in vehicles must have a certain stiffness so that they do not oscillate as a result of vibrations of the vehicle. It is advantageous in that context that at least one louver part has an I-shaped profile in at least a section of its length.
To attach the louver in the vehicle, one end is provided with a connection device. The connection device can have catch members so that louvers can easily be replaced in case of damage. In addition, a catch device facilitates assembly of the louver during the installation of the louver curtain or blinds.
If the second louver part is constructed in the shape of a tube in a manner such that the two louver parts can be shifted in each other in the manner of a telescope, the louver can have an attractive external appearance. In this instance, the installation of the louver is advantageously carried out such that the opening of the outer overlapping louver part is directed downward. Hence, no parts can fall in the slit between the two louver parts.
In order to achieve harmonious cooperation between the louvers and the window contour, at least one end of the louver can be adapted to conform with the course of the window edge at each position assumed by the louver when the louver curtain or blinds are closed.
A versatile shape is achieved if the louver is curved in the shape of a semicircle at one end, as viewed from its flat side. The semicircular shape has advantages, particularly when the lamellar curtain or blinds are open because the upper edge which projects into louver interior of the car is pleasantly rounded.
The pre-tension device is advantageously housed in the interior of the louver so it is not visible. A hollow space suitable for this purpose is, for example, the tube-like shape of the second louver part. The hollow space is closed by a cover so that the mounting of the pre-tension device is facilitated. The location of the cover in the hollow space is sufficiently short to prevent excess expansion of the pre-tension device. Moreover, the cover for closing the hollow space can be a closing cover to which the tube-shaped louver part is connected at one end.
An abutment device for the pre-tension device is advantageously provided on the cover. It consists, in the simplest case, of a pin. A similar abutment device can be formed inside at the end of the other louver part.
The pre-tension device preferably applies tension to the louver in the direction that shortens the longitudinal length of the louver. This prevents the louver from falling apart prior to assembly into the blind. It also is easier to handle it prior to the assembly. A compression member could also be used. In addition, one can use a simple rubber ring if the louver is subjected to pre-tension by pulling in the direction that shortens the longitudinal length.
One of the attachment devices for the louver in the assembled condition consists of a keyhole-type opening. As a result, the assembly and disassembly of the louver may be very simple. In this case, the keyhole-shaped opening can be provided with a recess so that a catch engagement results in cooperation with the pre-tension device.
The louver part advantageously consists of a plastic, for example, a thermoplastic.
The louver curtain according to the invention has two guide tracks which run side by side, following the opposite contours of each given window edge. In this manner, each louver is restrictively guided in a path at both front ends. It is effectively prevented from undergoing a pendulum-type motion as a result of centrifugal forces or other acceleration forces. In addition, the louvers cannot bump into each other. The louvers which are guided in the guide tracks further are adjustable in length according to the window contour.
To open the louver curtain, a coupling device is provided which connects each louver to the neighboring louvers. In this manner, only the louver which travels the longest distance during opening or closing needs to be driven. The louvers which are not driven are entrained via the coupling device during the closing, and, during the opening, they are entrained by the associated neighboring louver which is already in motion.
In each guide track, each louver preferably has its own slider with a peg extending out of the guide track to which the louver is anchored. If the peg can be separated from the louver, the sliders can each be mounted separately and inserted at the time of the mounting.
Since an advantage of louver curtains is that the louvers can be swiveled to regulate the inlet of light, it is advantageous for one of the pegs, and in particular only one of the pegs, to be connected to a given louver in a manner which prevents rotation. Such a connection which prevents rotation makes it possible for the peg to be in the shape of a hammer head that engages in a corresponding opening of the louver. The other peg, in contrast, is symmetrical with respect to rotation. The louver can turn on the peg. In this manner it is unnecessary to synchronize rotation of the pegs at both ends of a louver.
In order to move the slider which has traveled the largest stroke distance during the opening or closing, the slider can be provided with a threaded bore through which a screw spindle is provided. Such an arrangement is very space saving.
Rotation of the pegs can be effected in a simple manner with a small angular gearing which is housed in the interior of the slider. The angular gearing is advantageously a worm drive, where the worm wheel has a opening with polygonal profile. Using a corresponding polygonal cross section shaft, which runs through all the worms, the louvers can be adjusted in synchronism.
The coupling device, whose purpose is to entrain the louvers which are not driven during the opening, is a perforated band in the simplest case. The separation between the holes corresponds to the separation between the louvers in the open state. With the aid of this band it is possible to simultaneously cover the lower guide track, and thus there is no risk of a foreign matter falling in the guide track and interfering with the operation of the louver curtain or blinds.
Advantageously, the band which is used as a coupling device is longer than the curtain and when the louver curtain or blinds are open, covers the guide groove in the guide track. When not in use, the excess part of the band can be wound on a winding shaft by means of a spring drive.
Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings, in which: